BQ-123
Encyclopedia
BQ-123 is a cyclic peptide
consisting of five amino acid
s. The amino acid sequence is D-tryptamine
-D-aspartic acid
-L-proline
-D-valine
-L-leucine
.
BQ-123 is a selective ETA endothelin receptor antagonist
. As such, it is used as a biochemical tool in the study of endothelin receptor function.
Cyclic peptide
Cyclic peptides are polypeptide chains whose amino and carboxyl termini are themselves linked together with a peptide bond that forms a circular chain. A number of cyclic peptides have been discovered in nature and they can range anywhere from just a few amino acids in length, to hundreds...
consisting of five amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s. The amino acid sequence is D-tryptamine
Tryptamine
Tryptamine is a monoamine alkaloid found in plants, fungi, and animals. It is based around the indole ring structure, and is chemically related to the amino acid tryptophan, from which its name is derived...
-D-aspartic acid
Aspartic acid
Aspartic acid is an α-amino acid with the chemical formula HOOCCHCH2COOH. The carboxylate anion, salt, or ester of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins...
-L-proline
Proline
Proline is an α-amino acid, one of the twenty DNA-encoded amino acids. Its codons are CCU, CCC, CCA, and CCG. It is not an essential amino acid, which means that the human body can synthesize it. It is unique among the 20 protein-forming amino acids in that the α-amino group is secondary...
-D-valine
Valine
Valine is an α-amino acid with the chemical formula HO2CCHCH2. L-Valine is one of 20 proteinogenic amino acids. Its codons are GUU, GUC, GUA, and GUG. This essential amino acid is classified as nonpolar...
-L-leucine
Leucine
Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
.
BQ-123 is a selective ETA endothelin receptor antagonist
Endothelin receptor antagonist
A endothelin receptor antagonist is a drug that blocks endothelin receptors.Three main kinds of ERAs exist:* selective ETA receptor antagonists , which affect endothelin A receptors....
. As such, it is used as a biochemical tool in the study of endothelin receptor function.